Radiation

In the spring of 1980, paramedic Andrei Sergeev recorded a case of radiation sickness affecting one of his patients. How and when did the dying Soviet engineer come into contact with radiation, and why did the state security take such a serious interest in this case? Despite the fact that Andrei is preparing for his own wedding, he simply cannot refuse to participate in the investigation, not yet realizing the full seriousness of the matter, the threads of which extend far beyond the borders of Russia...